Pyrolyzing method and apparatus



Mal'l'l` 27, 1945. I N K, CHANEY 2,372,186

y PYROLYZING METHOD AND APPARATUS Filed July 5, 1941 e sheets-sheet 1u March 2?',v 1945. N. K. cHANEY 2,372,186

PROLYZING METHOD AND APPARATUS Filed July 5, 1941 6 Sheets-Sheet 2 LAzra SLWGMMM Sheegsl-Sheet. 3

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PYROLYZING METHOD AND APPARATUS Filed July 5, 1941 5 Sheets-Sheet 4 A a n p 225 mat/ 20/ S-SLM \Marg\h\ 27, 1945.

N. K. CHANEY PYROLYZING METHOD AND APPARATUS Filed July 5, 1941 6 Sheets-Sheet 5 /Zag - ALM/gdm March 27, 1945. N. K. CHANEY 2,372,186

PYROLYZING METHOD AND' APPARATUS Filed July 5. 1941 6 Sheets-Sheet 5 dized to undesired compounds.V

Patented Mar. 27, 1945 :fj: UNITED.'

PYBOLYZING METHOD AND APPARATUS Newcomb K, Chaney, Moylan, Pa., assignor to The United Gas Improvement Company, a corporai tion of Pennsylvania Application July 5, 1941, Serial No. 401,207 4 claims; (c1. 19e- 47) This invention relates to the pyrolysis of organioliluids which Atend to form combustible depositssuch as `carbon or carbonaceous material during their pyrolysis. An example of such material is fluid, hydrocarbon material, such as natural gas, reiinery oil gas and petroleum oil.

There are three general methods of pyrolyzing fluid hydrocarbon material with respect to the application of heat required for pyrolysis'. In cyclic processes such, for example, as oil gas processes and carburetted water gas processes, heat is stored in heat storage material during a heating step comprising the combustion of fuel with air, and ythe :fluid hydrocarbon material is pyrolyzed during a step called `the run, in which it is passed over the heated surfaces of the heat 'storage material. In continuousprocesses, such- 'asare employed in the petroleum oil industry for the production of motor fuel, the heat for pyrolysis isv applied through the walls of the tubes, in which the pyrolysis takes place. Y, The third general method comprises supplying of the heat for pyrolysis by the partial combustion of the fluid hydrocarbon materialbeing pyrolyzed.

Each of these general methods has advantages One of the objects of thepresent invention is to provide a method of and apparatus for pyrolyzing materials of the class described-which combine the advantages of the cyclic processes and apparatus of pyrolysis With the advantages of the indirect heating through the tube Wallsof the continuous` processes andi apparatus, and which also obviate their respective disadvantages.

Although as previously indicated the invention may be useful in the pyrolysis of a Wide class of materials, it is perhaps more especially adapted `for use in connection with the pyrolysis of iiuid hydrocarbon material vsuch as' for example, individual hydrocarbons or mixtures thereof for example as found in "natural gas, reiinery'oil gas and petroleum oil,inclu`d ing crude oil, cuts therefrom, and residuum's.l

i. For-purposes of convenience,` the'invention will be more particularly describedin connection with the pyrolysis of petroleum oil.

According to the present invention uid hydrocarbon material, such as petroleum oil, is pyrolyzed by passage through a'pyrolyzing chamber or' chambers as for example atube or tubes,

Vand disadvantages. In the third method, nainely that of partial combustion, the heating may be very' eiiicient, but' the resulting gas is very 'largely contaminated with inert nitrogen, unless relatively pureoxygen is employed for.l the partial combustion instead of air. Also products which are desired in unoxidized formv may be oxi- In the continuous processes, comprising heating through tube Walls, optimum temperatures, `and optimum temperature gradients may bemore readily maintained than in the Icyclic processes, which alternately store heat in heat storage materials such as refractories and employ the stored heat therein for pyrolysis.

in hydrogen, difficulties vare incurred due to the accumulation of such products on `the tube Walls,

resulting in eventual tube stoppage, unless there are frequent shut downs for, cleaning the tubes.

Moreoven such carbon accumulations on the tube `Walls may exert an undesired catalytic effect during the pyrolysis. n

In the cyclic processes,` carbon deposited lon ythe heat storage material'durin'g 'each pyrolysis step may be consumed inthe succeeding heating step. f

simultaneously heated through its or their walls by combustion in an adjoining pyrolyzing cham- 'ber or chambers which may 'also be a tube or tubes. VThe functions of the chambers employed for heating and for pyrolyzing are then reversed. Pyrolysis of the oil is then carried on in a chamloer previously employed for combustion, heat being supplied through a wall thereof from combustion simultaneously carried on in an adjoining chamber previously employed for pyrolysis. 'Suilcient air is supplied for combustion to` consume whatever additional fuel'vmaybe required as well as deposits of carbon on the chamber wall resulting from the previous pyrolysis.

. `.40 However, under conditions of pyrolysis suiii"v In other Words, adjoining chambers are alterlnately employed as v,combustion ues and as pyrolyzing chambers, heat for the pyrolysis being lsupplied from the combustion iiue to the pyrolv yzing chamber through their contiguous Walls or .50 .tures thereof will become more apparent to those i as through their common wall. y

Conditions of pyrolysis and the. material pyrolyzed vmaybe rsuch that little or no fuel may be vrequired in addition to the combustible material deposited during pyrolysis. e

Other objects of the invention and other feaskilled in the art as. the specification proceeds and inconnection with the vdescription of the accompanying figures which show forms of the invention chosen for illustration, and in which:

Figure 1 shows diagrammatically a top view of one form of the apparatus of the invention;

Figure 2 shows diagrammatically a bottom view of the apparatus of Figure 1;

Figure 3 shows, less diagrammatically and partly in elevation and partly in vertical section, a portion of the apparatus of Figure l, said section being. taken alongv the line I-I. of Figure 1;

Figure 4 shows` in horizontal section another form of the apparatus of the invention, said horizontal section being taken through the tubes thereof;

Figure 5 shows a bottom view of the. apparatus of Figure 4;

Figure 6 shows a top View of.' the apparatus. of: Figure 4;

Figure 7 shows a second horizontal section of the apparatus-of Figure 4, saidy section being taken above the tubes and below the cross-over connections of Figure 6.

Figure 8 shows in. horizontal section a modiiied form of the tubev arrangement of the appa-- ratus of Figure 1.

Referring to Figures l, 2, and 3, the nested vertical tubes I to 63 inclusive are arranged within the heat insulating wall G4. As illustrated; the adjoining tubesI have-common metal` walls. It is tc be understood', however, that; the. walls of adjoining' tubes may be contiguousinstead of commonv and may bea of= eitherl materials than metal, such, for' instance, as refractories.

l-lowever,l materials of high? heatn conductivity are preferred and if reiractories arey employed tor the tube walls, it is preferred to employ such refractories asV carborundum, which have relatively high heat conductivity:

Metals if employed should, of. course-, be; sufficiently heat resisting for the temperaturesy to which they are exposed.

The tubes are preferably empty as shown` or at least substantially devoid; of packing.

Each tube is. provided at its. top with means for admitting petroleum oil, steam, air and uid fuel.. The-fiiuid fuelmay be any desired or avail,- able fuel, such ascombustible gas fuel oil, tar, etc.

Petroleum oil. line 66 steam, line 61, fuel line 68, and air line 69 areeach connected with. tube 1 by valved lines 10. 1|, 12 and 1.3` respectively;

`with tubes 6K and I4 by valved lines 14, 15, 16

and 11 respectively; with tubes 5f. I3., andv 2| by valved lines 19,. 80, 8| and 82, respectively; with tubes 4, I2, 2Iiand 28 by valved lines 84, 95, 85 and 81, respectively; with tubes 3, II, |9-, 21 and 3,5 by valved lines 89 90, 9|., and 92', re Spectively, with tubes 2,A l0, I8, 26, 34 and 42, by

valved lines 94', 9.5, 9.6, and 9.1, respectively; with' tubes I, 9, I1, 2.5 33 Ill` and 49 by valved lines 99, |99, IIJI., and |02., respectively; with tubes 8, i6, 24,. 3.2., 40,. |18V ,and 5S by valved lines |04,

. |05, |05, and H11., respectively; with tubes. I5, 23,

3|., 39 4.1, 55 and 63 by valved lines |09, IIU., and ||2 respectively; with, tubes 2.2,. 30, 313,I 46, 54' and 62 by valved lines. H3, H4, |,I5 and IIB respectively; with tubes 29s 3.1,. 45, 5,3, and 6|. by

valved lines H1,l |18,k I'Iand IZDreSpectively; withtubesj, 44, 52 and 60 by valved lines |2I, |22, |23 and |24', respectively;- with tubes 43, 5| and 59. by valved lines |25, |26, |21' and |28, respectivelyywith tubes 5U and 5.8 by valved lines |29, |39, IBI; and' |32, respectively; with tube 51 by valved' lines. |34 |35 |35 and |531 respectively.

As, shown particularly in Figure 2,A at their bottoms the, tubes are connected in diagonal rows by connections' |40', IM, |42, |43, I, |45, |45,

|41, |48, |45, |5u, |5|, |52, |53 and |54 with both the combustion gas off-take |55 and the make-gas olf-take I 56, by valved branch connections.

tops thereof; the oil being vaporized and pyrolyzed 1n passage downwardly through the tubes and the resultant make-gas being drawn on from y the tube' bottoms.

As will be seen the arrangement illustrated in these figures, is` such that tubes being employed for pyrolysis of oil are surrounded on all four simultaneously being emsides by adjoining tubes necessary heat for pyrol- `ysis being delivered from the heating tubes to the pyrolyzing tubes through the common tube Walls. Tubes employed for heatingA are surrounded by for pyrol sis an cooled thereby. l y d me ucts from the bottoms ofthe tubes.

It will be understood, that between reversals. the apparatus may be, purged. For example, the tubes employedV for pyrolysis and combustion may be purged with steam supplied to their tops after the oil has been shut oil? in the case of tubes employed for pyrolysis and after the fuel and air or air alone hasbeen shut off in the case of tubes employed for combustion.

Inasmuch as the tubes` at the extreme ends of the'varlous. rows if employed for pyrolysis are not entlrely surrounded by tubes employed for heating, 1t may be` preferred to omit an oil pyrolyzing operation. in these tubes; vand to this end it may be preferred. not. to. furnish these tubesY with oil and If such connections are furpermit the oilsand steam supplied therethrough to be shut-oft' at such tubes. If desired, individual control of supply of fluids to and of the withdrawal of productsl from any otherindividual tube may also be provided.

As an example of the division of functions of the tubes of Figure 1 at an assumed instant of operation, the various diagonal rows of tubes have been marked H or P, depending upon whether employed .at such assumed time, for heatingor for pyrolysis, respectively. In the'case illustrated, the tubes at the ends of the diagonal rows are not employed for pyrolysis. As illustrated, the row containing tubes 5 and |'4 is employed for heating; the tube I3 for pyrol heating; row containing tubes I3 and`21 for pyrolysis; the row containing tubes 2, I0, I8, 25, and 42 for heating; row containing tubes 9, I1, 25", 33, andl4| for pyrolysis; the row containing tubes 8, I6, 24, 32, 40, 48 and 56 for heating; the

row containing tubes 23, 3|, 39, 41, and 55 forrv f pyrolysis; the row containing tubes 22, 30, 38, 48,1 54'and 62 for heating; the row containing tubes 31, 45,'and 53 for pyrolysis; the row containingA tubes 36, 44, 52, and 60 forheating; the tube 5I forpyrolysis; and the row containing tubes 5|? and 58 for heating. i

As previously stated, the period between the reversals of tube functions may be` of any desired length. l It may be preferred to reverse the tubes in short cycles or it maybe preferred to operate with a long period between reversals.

The length of these cycleswill, of course, depend among other thingsupon the rapidity of carbon accumulation on the walls of the tube when employed vfor pyrolysis. i `1 The rapidity of carbon accumulation will defpend upon the materialpyrolyzed and upon the severity of the pyrolysis as well as vupon such factors as the particular material employed for the tube walls and the character of'its surface. f'

It may valso dependupon the presence or absence of a diluent supplied as a pyrolyzing environment `and upon the character of' the diluent supplied,

if any.

Referring to Figures 4, 5, 6 and 7 these figures illustrate a modified form of the invention illus trated in the previous figures.

Numerals 200, 20|, 202 and 203 indicate tubes which are alternately employed for pyrolysis and for heating. As can be seen from Figure '1, each l I tube is provided with a supply of petroleum/ cil for pyrolysis `from oil line 204. Oil line 204 is connected by the valved connection 205 with tubes 200 and 203 by way of pipe 30| and by the valved connection 206 with tubes 20| and 202 `way of pipe 302. 4

- Each tube is provided at its top with a supply of Quid fuel such as, for example, tar from the fuel line' 201. The tar line 201 is connected by valved connection 208 with tubes 20| and valved connection 209 with tubes 200 and 203.` l

Each tube is provided at'its top with a supply 'of steam from the steam line 2 I 0. Steam line `2 I 0 is connected by the valved connection 2I| with withinthe outer shell 220. which is surrounded by the insulating material 22|. The flue 222 ad joins tube 200; nue 223 adioins tube 20|: the iiue 224n adjoins tube 202, and flue 225 adjoins tube The flue 222 is connected to the bottoms of 202 and by v4the yysis; row containing tubes 4, |2, 20 and 28 for lli tubes 20| and'202 by the valved'connection 226;v the ue 223 is connected tothe bottom oftubes 200 and 203 by the valved connection 221. The

nue 224 is connected to tubes 200 and 203 by the valved connection 228. The nue 225 is connectd to tubes20| and 202 by valved connection 229.

The ilues 222, 223, 224 and 225 at their bottoms are provided with the air connections V230, 23|. 232 and 233 respectively, and with the steam connections 234, 235, 236 and 231, respectively.

At their tops ilues 222 and 225 are connected to the stack 238 by valved connection 239 as can be seen `from Figure 6. The flues 223 and`224 are connected to the stack 238 by the valved connection 240.

Flue 222 is also connected with the top of the tube 200 by valved connection 24I. Flue 223 is also connected to the top of tube 20| by valved connection 242. Flue 224 is also connected to the top of tubel202 by the valved connection 243.

Flue 225 is also connected to the top of tube 203 by the valved connection 244.

The adjoining walls of the tubes and ues may be formed of metal or of refractori'es. If refractories are employed, refractory material of high heat yconductivity is preferred, such as carborundum, though other refractories may be used.

Each of the ilues 222, 223, 224 and 225 are provided near their bottoms and above the entrances of the air supplies 230, 23|, 232 and 233 with horizontal partitions provided with openings and adapted to serve as means for distribution of fluids throughout the respective flues. Such a partition in the case of flues 225 is indicated at 250 provided with openings at 25| and 252.A

The tubes and Ilues are preferably empty as shown or at least substantially devoid of pack- As an example of the operation of the apparatus of Figures 4 to '7 inclusive, it will be assumed that tubes 200 and 203 are being employed for pyrolysis and tubes 20| and 202 are being employed for heating.

Petroleum oil is supplied to the tops of tubes 200 and 203 through oil line 204 and valved connection 205. At the same time, steam is supplied to these tubes` through the steam supply line 2|0 and the valved connection 2| I.

The oil is vaporized in these tubes in the presence` of the steam and the oil pyrolyzed in its passage downwardly through the tubes.

The resultant make-gas issues from the bottoms of the tubes and passes by way of the valved connection 2|1 to the make-gas olf-take 2|5 and thence to Storage, condensation or other treatment.

At the same time, fuel and air are supplied to the tops of tubes 20| and 202. The fuel such for example, as tar is supplied from fuel line 201 through the valved connection 208.`

The air is supplied to tube 20| through airsupply 23|, flue 223, and the valved connection 242. Air is supplied to tube 202 throu'gh'air supply line 232. ilue 224, and the valved connection 243..

The fuel supplied is burned withfthe air in tubes 20| and 202 heating tubes 200 and 203 through the common rwalls shared with these tubes.

The combustion products pass downward from tube 20|, and pass by Way of valved connection 22B into ue 222, and upwardly through that ueheating the two outer walls ofv tube 200.

From flue 222 the combustion products pass by way of valved connection239 to the'stack 238.

The combustion products from tube 202 pass by way of valved connection 229 to the flue 225,

and pass upwardly through that flue heatingy the two outer walls of tube 203,4 andthence passing by way of connection 239 to stack 238.v

The functions of the two sets oftubes, theset 200 and 203 and the set 20| `and 202, are then reversed and the set 200 and 203 becomes the heating set of tubes and the set 20| and 202 becomes the pyrolyzingset of tubes. The operation isfsimilar to that just previously described except thatfuel and air are supplied to the set 200 and 203` and oil and steam to the set 20| and 202 and the necessary valve changes are made to lead the make-gas 01T from the bottoms of tubes 20| and 202 to theV make-gas line 2|5, and combustion products from the bottoms of tubes 200 and 203, up through nues 224 and 223, respectively, and thence to thestack. i

Between reversals the apparatus may be purged ofcombustion products and make-gas, the former by steam admitted through steam supplies 234 and 231 or steam supplies 235 and 236, depending upon which tubes are being employed for heating, the latter by steam admitted through steam supply 2| 0 and connection 2|| or 2|2 depending upon which tubes are being employed for pyrolysis.

It will be noted thatthe tubes employed for pyrolysis are heated on all four sides; on two sides through the walls of. the heating tubes and on the4 other two sides by vcombustion products passed from the heating tubes around these other twofsides.

It will also be noted that the heating tubesare cooled on a-ll four sides; on two sides, throu-gh the walls of the heating tubes by the oil, steam, oil vapors and gas iiowing through the pyrolyzing tubes, and on the other two sides by the air for combustion.

As stated in connection with Figures 1, 2 and 3, the period between reversals of the functions ofthe tubes may be of any desiredlength and will vary with the materials pyrolyzed, the severity f the pyrolysis, and with the presence or absence of inert gases introduced during the pyrolysis as well as with the character of the tube walls.`

As in the case of the apparatus of Figures 1, 2

. and 3, any accumulations of carbon upon the walls of the tubes during pyrolysis of the oil may be readily consumed during the succeeding period, when that particular tube is employed for heating,- sufficient air being admitted to consume the carbonf accumulations as Well as any additional fuel supplied for heating.

It will be seen, therefore, that the invention combines the heating through tube walls of conventional continuous pyrolysis processes which permits close control of temperatures and temperature gradients, with the periodic removal of carbon accumulations of conventional cyclic pyrolyzing processes.

The invention, although adapted for use in the pyrolysis of iiuid hydrocarbon material generally, is' perhaps more particularlydesirable in connection with the pyrolysis of petroleum' oilA for they production of high yields of valuable unsaturated resin-forming hydrocarbons such as, for example, butadiene, cyclopentadiene, dicyclopen- 1ra-diene, isoprene, piperylene, styrene, methyl styrene and others whose composition is not definitely determined as yet. There are also produced saturated aromatic compounds such as benzene, toluene, xylene,` naphthalene and others as yet unidentified, as well as normally gaseous saturated and,y unsaturated hydrocarbons, such as methhydrocarbon material very poor in hydrogen isv also produced especially when operating at relatively high .temperatures and/or with relatively long time of contact. Such carbon tends to deposit on surfaces in contact with the material undergoing pyrolysis.

' In such petroleum oil pyrolysis, oil is pyrolyzed in vapor phase in the presence of inert diluent gas such for example, as steam with close control of conditions governing the severity andcharacter of pyrolysis. Itis particularly desirable in connection vwith suchpyrolysis to beable to maintain closely optimum temperatures and optimum temperature, gradientsv throughout ,the course of the pyrolysis. This close control is more necessary in such a case than ifthe process is directed principally-to the p rcductionof combustible gas. In the latter case, a relatively Wide latitude of conditions may produce the s ame average result asmeasured by the thermsv in the nished gas. Deposits of carbon on the walls of the pyrolyzing chambers have an undesirable catalytic effect upon the yield of certain ofthe above mentioned unsaturated compounds.

It will be obvious tothose skilled in the art, that many modifications of the apparatus chosen for illustration andthe method as described may be made Without departing from the spirit of the invention. For example, in connection with the apparatus of Figure 1 the outer tubes when employed for pyrolysis might be heated by passing around their outer walls theproducts of com- 'bustion` from tubes employed for heating as is illustrated in the case of the apparatus of Figures 4, 5, 6 and 7.

The points of admission of the oil, steam, ,fuel and air may be varied widely from those illustrated as well as the points of withdrawal of make-gas and combustion products.

For example, both the pyrolysis and the combustion may be conducted upwardly through the tubes or the combustion and pyrolysisv might be conducted in countercurrent relation to each other, for example, the combustion conducted downward andthe pyrolysis upward.

Petroleum oil and other liquids when employed for pyrolysis may be introduced as liquids or may be vaporized prior to introduction into the pyrolyzing chambers.

As previouslystated under some conditions it may not be necessary to introduce additional fuel.

The arrangements of tubes employed for pyrolysis and heating may be varied from those described. For example, in the apparatus of Figure 1, alternate rows of tubes other than diagonal rows might be divided as to function. Other arrangements might be employed.

The tubes need not be vertical, but may be horizontal or otherwisa,

The pyrolyzing and the heating chambers may be of any convenient shape and constructed of any desirablek material.

For example, in Figure 8 are shown in horizontalcross-section, tubes which have a hexagonal shape in that plane andA which may be employed in, alternate rows .for heating and pyrolysis as indicated by the letters H for heating and P for pyrolysis.

Apparatus such as described if d esired, may be arranged in series, the products of pyrolysis from one apparatus passing with or without in` tervening treatment to another apparatus for further pyrolysis therein.

In the claims the term petroleum oil is intended to include crude oil, a cut or cuts therefrom and residuums Whether introduced in liquid or vapor phase. y

In the claimsI the term adjoining is intended to apply to a common wall as Well as to contiguous walls and to chambers having a common wall as well as to chambers having contiguous Walls. y

The terms comprises and comprising in the claims are employed in their usually accepted meanings and do not exclude the employment of other steps or the presence of other means, than those described.

Therefore, changes, omissions, additions, substitutions and/or modifications may be made Within the scope of the claims without departing from the spirit of the invention which is intended to be limited only as required by the prior art.

I claim:

l. A method for pyrolyzing fluid hydrocarbon material in a plurality of chambers in heat transfer relation one with another through adjoining walls having a heat conductivity at least as high as that of carborundum refractory material, which comprises pyrolyzing said fluid hydrocarbon material in certain of said chambers, simultaneously carrying on combustion in a plurality of other chambers adjoining said chambers employed for pyrolysis, a chamber when employed for pyrolysis being surrounded' by a plurality of adjoining chambers employed for combustion and a chamber when employed for combustion being also surrounded by a plurality of adjoining chambers employed for pyrolysis, vvhereby chambers when employed for pyrolysis are heated through their Walls by surrounding chambers employed for combustion and chambers when employed for combustion are cooled through their walls by surrounding chambers employed for pyrolysis.

2. A method for vaporizing and pyrolyzing liquid hydrcarbon material in a plurality of chambers in heat transfer relation one with another through adjoining walls, which comprises supplying said liquid hydrocarbon material to a chamber for vaporization and pyrolysis therein, simultaneously by admission of fluid fuel and air thereto carrying on combustion in a chamber one wall of which is in adjoining relation to a wall of said chamber employed for vaporization and pyrolysis, thereby heating said chamber employed for vaporization and pyrolysis-through said adjoining walls, leading off the reslulting products of combustion in heat transferk relation to another wall of said chamber employed for vaporization and pyrolysis, thereafter supplying said liquid hydrocarbon material to said chamber previously employed for combustion for vaporlzation and pyrolysis therein, heating said last named chamberthrough said adjoining walls by combustion carried on in said chamber previously employed for vaporization and pyrolysis, and leading oil the resulting products of said last named combustion in heat transfer relation with another wall of said chamber previously employed for combustion.

3. Apparatus for vaporizing and pyrolyzing liq..

`uid hydrocarbon material comprising a plurality of pyrolyzing chambers substantially devoid of packing and in heat transfer relation one with another through adjoining walls, means for alternately admitting said fluid hydrocarbon material for vaporization and pyrolysis and air for combustion of carbonaceous material deposited as a result of pyrolysis of said liquid hydrocarbon material to each of adjoining chambers, said means being arranged to admit said liquid hydrocarbon material to one chamber for vaporization and pyrolysis therein While simultaneously.

admitting air to an adjoining chamber to effect combustion therein, and means for leading o combustion products from a chamber employed for combustion in heat transfer relation with a .wall ofa chamber employed for pyrolysis.

4. Apparatus for pyrolyzing fluid hydrocarbon material comprising a plurality of chambers in heat transfer relation one with another through adjoining walls of material having a heat conductivity at least as high as that of carborundum refractory material, means for supplying fluid hydrocarbon material to certain of said chambers for pyrolysis therein together with means for simultaneously carrying on combustion in a plurality of chambers adjoining and surrounding individual chambers in which pyrolysis is being effected, and means for alternately carrying on combustion in chambers previously employed for pyrolysis together with means for simultaneously supplying fluid hydrocarbon material for pyrolysis to a plurality of chambers previously employed for combustion which adjoin and surround individual chambers at that time employed for combustion.

NEWCOMB K. CHANEY. 

